ST25R3911 APDU response interpretation

[Stasevich]

Hello

Help me understand the interpretation of the APDU command response.

Hardware : ST25R3911B-DISCO , Logic analyser , Visa NFC card

Action: send custom APDU and parse response

The problem is : non-identical data (APDU answ.) received through the SPI protocol analyzer ST25R pins AND APDU answ. which is displayed in the application window

Moreover, why does the APDU data response appears along the MISO and MOSI lines simultaneously and in fragments ?

[Brian TIDAL]

Hi,

can you check the configuration of your Logic Analyzer SPI decoder : it should be configured to sample SPI data on falling edge of the SPI CLK.

Regarding " why does the APDU data response appears along the MISO and MOSI lines simultaneously", the content of the MOSI is not meaningful when receiving data on the MISO.

Rgds

BT

[Stasevich]

Regarding the first point - you are right, the problem was in the settings of the interpreter

And thnk for answer to the second question ) because the data on the two lines was really misleading

[Brian TIDAL · Accepted solution]

Thanks for your feedback.

The C-APDU you sent is a ISO 7616 SELECT with DF name = 2PAY.SYS.DDF01

The R-APDU received has a FCI followed by status=9000 ("Normal processing")

This means your basic communication with the card is operational.

If your application is related to EMVCo, I would recommend to have a look to ST25R3911B-EMVCO and ST25R3916-EMVCO kits.

Rgds

BT